1. Field of the Invention
The present invention relates to a device for use in exterminating insect pests. More specifically, the invention relates to a device for dispersing a pesticide that kills fire ants.
2. Discussion of Background
Fire ant colonies are prevalent in the southeastern United States and pose a serious problem. A fire ant colony can be identified by a large crustaceous mound of earth. The presence of fire ant colonies in lawns and in parks is a nuisance and a hazard. The fire ant's painful sting, coupled with its tendency to attack in numbers, is a threat, especially to both children and small domestic animals.
Fire ants live below the surface of the ground where they form a network of tunnels. Their use of tunnels and their ability to quickly evacuate part of a colony from one part of the tunnel complex, makes the eradication of fire ants difficult.
A number of pesticides and devices for use with pesticides are available for killing fire ants. Usually, the pesticides are applied to the surface of the ground on a fire ant mound in the hopes that the ants will carry pesticides into the colony below. This approach is only marginally effective.
Recognizing the need to penetrate below the surface in order to effectively eradicate a fire ant colony, current devices for use with pesticides include a number of probes or lances that are inserted into the mound. For example, U.S. Pat. No. 5,109,629 issued to King et al teaches a device that introduces a vaporized pesticide into a fire ant colony via a probe. The probe is equipped with holes at one end through which the poison enters the fire ant colony. Similarly, U.S. Pat. No. 4,756,118 issued to Evans II discloses a pressurized injection gun having a lance with a tip through which liquid or vaporous poison can be forced into the colony.
Current devices are capable of delivering poison in a solid, liquid or vaporous state. Several of these heat liquid insecticides to form a vapor and thereafter introduce the vapor into the fire ant colony. Other apparatus introduce a combination of insecticide and other fluid into the fire ant colony. For example, U.S. Pat. No. 4,160,336 issued to Query combines an insecticide and a refrigerant for delivery into the fire ant colony via a probe.
Many of these designs are more suitable for professional use rather than for use by a homeowner; they are more complicated and involve high pressure and high or low temperatures. Furthermore, the simpler designs that might be suitable for home use do not address the problem of blockage of probe holes, blockage that occurs when soil becomes lodged in these holes. Typically, the lance or probe becomes blocked by soil as the device is pushed through the soil and into the fire ant colony. Blockage by soil prevents the effective eradication of a fire ant colony and limits the effectiveness of the device because fire ants respond to threat by either attacking the aggressor or by quickly evacuating the colony.
Given these conditions, there is a need for a simple, relatively inexpensive device, that can be used by a homeowner, and that is capable of quickly delivering liquid insecticide directly into a fire ant colony.